I am assuming at the time that any tab is worth X amounts of points, whether it be chords format, tab format or GP/equivalent format.

If this is the case, it needs to be changed. If it's not the case, this thread should be ignored.

Chords is the most basic form of transcription. Tab is a more detailed approach, while GP typically tries to imitate the entire composition.
From what I've seen, the top contributors on UG by far are the chord submitters. Some of them mash out on average multiple "tabs" per day.
The work of a chord tab is typically googling the lyrics and transcribing the general chords of a song. For a decent transcriber, this can be done in less than half an hour. Tabbing would take a few hours and tabbing more instruments accurately easily takes 10+ hours depending on the complexity of the song.

My point here is that the effort in various forms of submissions vary significantly and therefore should have different value in the ranking system of UG.

I noticed over new years that UG had some public tribute toward top contributors and that the "winner" for the year was some guy who spams out a massive amount of these chord format tabs and had submitted over 600 in a year or something like that (maybe more).
This is an impossible achievement for people who make more detailed tabs and therefore I suggest a more balanced points system on UG.
A side effect of this may be encouraging more GP submissions and a larger catalog of tabs for Tab Pro.

Most of that is true enough. But I'm not sure a complete redo of the whole rating system based on that would work out. Or be wise.

But maybe UG can add a separate rating system based on the contribution type itself (like tabs, GP, chords, etc.) without having to remove the old rating scores. Kind of like how they have it now with top tabbers, top contributors, and top review writers and such separated.

You raise some valid points, something I'd been thinking about, but I can't see the whole ratings system being overhauled , the work involved in that must be huge and then you get into the problem of why should a really basic bass tab get the same as a more complex guitar tab with full solos.....

Anyway, I shouldn't worry too much about the whole tab rating/points thing while there's people with multiple accounts rating their own tabs with 5 stars or using a group of friends to do it regardless of the quality.......